ID cable for Control Panel

There's nothing to that effect in BS 7671 to the best of my knowledge.

What sort of equipment are we talking about? if it's machinery rather than building installation, other standards may apply,

Individual company internal standards or specifications of a contract may impose more detailed requirements though.

   - Andy.

Not a wiring regulation as such. House style, and maybe dictated by customers in some cases

Mike

Agree with the other replies that it depends on which convention (if any) the contract or specification refers to. But to clarify... I think most, if not all, will be left to right as in C-2553 rather than 3552-C; but the variation is whether is reads left to right towards the terminal or left to right away from the terminal.

Thank you guys, it is control panel for manufacturing..  

Juan Kiriluk said:

Thank you guys, it is control panel for manufacturing..  

Interested what the function of those conductors is?

Usually BS EN 60204-1 applies, and conductors are typically Red, Black, Blue, Orange or Green-and-Yellow dependent on function? I understand there may be a reason it's white, and it is permitted in the standard ... but sometimes it's Neutral in machinery produced for USA and Canada